1. Field of the Invention
The present invention concerns a device for counting particles of ionizing radiation and its application to implementing a method of measuring leakage between the primary and secondary circuits of a steam generator.
2. Description of the Prior Art
Devices for counting particles of ionizing radiation currently employed enable direct counting of ionizing particles, this counting being usually effected in the single case of counting a specific type of ionizing particle, actually a corresponding single energy level of these particles. However, in the case of particles emitted at high energy levels such as .gamma. photons with an energy greater than 4.5 MeV, detecting and in particular measuring the corresponding flowrate of the support radioactive effluent, especially in the case of low and very low flowrates, that is to say for a low emission intensity of the radioactive effluent, is usually made difficult by drift dependent on operating conditions and temperature in particular. Given the high sensitivity needed for measuring at low emission intensities, the effect of such unwanted drift is to falsify the measurment results and consequently render them useless for showing up and measuring low rates of leakage of radioactive effluent.
An object of the present invention is to remedy the aforementioned disadvantages through the implementation of a device for counting particles of ionizing radiation in which the effects of measurement drift are eliminated.
Another object of the present invention is the implementation of a device for counting particles of ionizing radiation in which energy level calibration is applied continuously so as to authorize the counting of pulses generated by particles of ionizing radiation, this calibration being relative to the energy level of particles of ionizing radiation from a so-called reference source.
Another object of the present invention is the implementation of a device for counting particles of ionizing radiation in which the energy spectrum of the reference ionizing radiation lies outside the energy spectrum of the ionizing radiation to be measured.
A further object of the present invention is the use of a device for counting particles of ionizing radiation to implement a method of detecting and measuring the rate of leakage between the primary and secondary circuits of a steam generator.